Objects Detected in Universe May Be the Most Distant Ever Sighted

By JOHN NOBLE WILFORD, Special to the New York Times

Published: January 14, 1988

AUSTIN, Tex., Jan. 13—
Astronomers, applying new technologies for looking deeper into time and space, have detected what they believe may be the oldest and most distant objects ever seen in the universe.

These objects appear to be beyond any observed quasar, those mysterious sources of light that until now were the most distant objects detected. They appear to be far beyond any known galaxies of stars. They may be so far away, and thus so old, perhaps 17 billion years old, that their radiations are coming from the creation of some of the universe's first galaxies.

The discovery of bright infrared radiation from these objects, tentatively called primeval galaxy candidates, was described here today at a meeting of the American Astronomical Society.

Scientists do not know why, how or when galaxies formed. They hope that the new discovery will help fill one of the major gaps in astronomer's knowledge of the formation of the universe.

Astronomers from the University of Arizona's Steward Observatory found the objects using an array of powerful infrared detectors that were developed for military heat-sensing observations. The technology has only now been declassified and used by astronomers.

Although the findings are preliminary and must be confirmed by further observations, other astronomers described the research as sound, the interpretation as reasonable and the prospect of seeing the formation of galaxies as one of the most exciting developments in astronomy today.

Richard Elston, leader of the University of Arizona team, reported that the infrared brightness of the objects, estimates of their distance and other properties were strong evidence that they were primeval galaxies.

''If these infrared sources are galaxies,'' Mr. Elston said, ''we're probably seeing them as they were forming, right when they were making most of their stars.''

Astronomers have many theories of galaxy formation, but virtually no observational evidence except for the mature galaxies. Seeing galaxies so far out in an expanding universe is to see them in an early stage of development, not too long after the theorized ''Big Bang'' that created the universe. Astronomers Are Excited

The new discoveries thus could give astronomers their first glimpse of when and how gases and dust first clumped together in the young universe to form stars in vast collections known as galaxies. Scientists then might have to revise many of their concepts of the evolution of the universe.

''The work looks pretty good to me,'' said Harding E. Smith, a professor of astronomy at the University of California at San Diego who is a specialist in galaxy studies. ''All this is terribly exciting.''

Patrick J. McCarthy, an astronomer at the University of California, Berkeley, said: ''It's going to be extremely difficult to prove that they are primeval galaxies. But if you add all the evidence together it looks like a very good bet.''

Mr. Elston made the discovery last spring as part of his doctoral dissertation research. Others on the team were Marcia L. Rieke and George Rieke, also of the University of Arizona.

The astronomers used the university's relatively small 61-inch telescope in the Santa Catalina Mountains north of Tucson. But they equipped the telecope with an imaging system containing an array of more than 4,000 tiny infrared-sensitive detectors. They were embedded on a one-eighth inch square mercury-cadmium-telluride chip.

The device, developed by Rockwell International Inc., enabled the astronomers to accomplish in one night what it would have taken them 4,000 nights to do as recently as 1985, when single-detector devices were all astronomers had to work with. Viewing Area Chosen Randomly

Mr. Elston pointed the telescope toward a dark area of the sky away from the brightness of the Milky Way. The choice of viewing areas, he said in an interview, was random, which made him believe that similar objects will be found nearly anywhere astronomers look out at the fringe of space.

In one night's work, the astronomers got fuzzy images of several apparently distant sources of infrared radiation. Observations in the visible light confirmed the existence of two of the objects as faint points of light.

Analysis of the infrared images, Mr. Elston said, revealed that they were ''extremely red,'' showing up 20 times brighter in infrared than in visible light. This was ''consistent,'' he said, with theoretical models of what a primeval galaxy should look like.

Further analysis of the radiation showed the light was stretched out to longer wavelengths and thus a redder color. The degree to which light is stretched is expressed as a red shift, which affords astronomers their best method for estimating the distance the object is out in space. The greater the red shift, the farther away the object is. Exact Distances Unknown

By Mr. Elston's calculations, the objects detected probably have a red shift of at least 6 - that is, the light has had its wavelength stretched by 600 percent. The most distant quasar, discovered recently, has a red shift of 4.43.

Converting a red shift to distance, and so to a object's place in time, depends on knowing the expansion rate of the universe, something astronomers are not certain of. This is why cosmologists speak of the universe being from 10 billion to 20 billion years old.

Assuming a version of the latter model, which Mr. Elston did in his analysis, the objects he detected would be about 17 billion light years away. The radiation he observed represents events occurring 17 billion years ago.